Stencil sheet



Patented July 23, 1940 UNITED STATES PATENT OFFICE STENCIL SHEET Shinjiro Horii, Kanda-ku, Tokyo, Japan No Drawing. Application June 21, 1939, Serial No. 280,381. In Japan May 16, 1939 2 Claims.

corporation of soybean casein with synthetic resins, emulsified and softened by emulsifiers and tempering agents or softening agents and dispersed into water or other dispersing medium, constitutes a highly efiicient coating for stencil sheets, possessing flexibility and durability.

The soybean casein is specially prepared by extracting soybean with a solvent, such, for example, as a mixed solvent comprising methyl or ethyl alcohol and benzine or benzol, and drying out the solvent at low temperature. The temperature of the extraction and the drying must be kept as low as possible, avoiding the deterioration of the protein material.

Synthetic resins suitable for use with the protein material may be prepared by, for example, thecondensation. of aldehydes with phenols or amines, by the reaction of acid anhydrides with polyhydric alcohols and by the polymerization of unsaturated hydrocarbons or vinyl compounds.

These polymerizable compounds may be incor- V porated with certain modifying agents before they are polymerized, thereby producing a suitably modified resin produced in accordance with the modifying agents incorporated with.

the mixture of soybean casein with synthetic resins by the aid of emulsifying agents, such as soaps, Turkey-red oil, sulphate salts of the highor fatty alcohols, triethanolamine, lecithins or the like, and tempering agents, such as ethylene glycol, glycerine, sorbitol, iattyoils, fats, waxes, heavy mineral oils, naphthenic acid esters or a mixture containing two or more of these, and dispersing the mixture into water or other suitable dispersing medium, such as alcohols, solvent naphtha, cyclohexanol, butyl acetate, ethyl ethers of glycol .or the like. Then the prepared coating material may be coated or impregnated with the fibrous base, such as Japanese Yoshino paper, in the usual manner.

The proportions of the ingredients of the coating material may vary according to several circumstances. The following is an example:

Parts by weight Soybean casein 20 Phenolic resin 5 Triethanolamine 5 Turkey-red 011-. 10 Castor oil 20 Heavy mineral oil 10 Cyclohexanol 20\ Water 200 

